"While a more exhaustive analysis would alter some of the details of the present study," Spitzer wrote, "it would probably not change the chief conclusion -- that such a scientific tool, if practically feasible, could revolutionize￼ astronomical techniques and open up completely new vistas of astronomical research."

Spitzer's original paper was republished in The Astronomical Quarterly in 1990, and he added a postscript about the impact of his paper, which is actually a remarkable document itself. How does an idea written down somehow become a satellite flying around Earth?

"Since this 1946 paper did not appear in the astronomical literature and was not generally distributed in reprint form, its direct influence on other astronomers must have been almost negligible," Spitzer writes. "Its chief effect was on me. My studies convinced me that a large space telescope would revolutionize astronomy and might well be launched in my lifetime."

From that point forward, he promoted the creation and launch of such a telescope. Over his years at Princeton, he worked out some of the technical problems and talked with other astronomers. Twenty years later, during the heat of the space race, the National Academy of Science asked Spitzer to head up a committee "on the Large Space Telescope" in 1966, when such a project began to look more feasible. They issued a report in 1969.

"During the work on that report, possible astronomical observing programs were discussed in detail with various groups of astronomers, who in the course of these discussions generally became enthusiastic supporters of such a large and powerful telescope," he recalled. "This support was a major element in Congressional approval of the large telescope project in 1977."

While people were aware of the limitations of earth-based telescopes, it was Spitzer who articulated and promoted the vision of the orbital observatory, NASA historian Gabriel Okolski agreed.

It took a good eight years to get funding, and another 13 to build and launch the Hubble. And, in some ways, that is the crowning glory of science: the timescales. Spitzer saw this thing through for 30 years to completion!

I don't think that kind of life approach comes naturally to people. It's a remarkable set of institutions that makes such long-term thinking possible.

This weekend, I was talking with a graduate student who works on stem cells in the heart. She said, "The problems I'm thinking about now are probably the problems I'll be thinking about when I die."